[PATCH 4.4 88/99] PM / sleep: Handle failures in device_suspend_late() consistently

From: Greg Kroah-Hartman
Date: Sun Jun 05 2016 - 18:51:03 EST

4.4-stable review patch. If anyone has any objections, please let me know.


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

commit 3a17fb329da68cb00558721aff876a80bba2fdb9 upstream.

Grygorii Strashko reports:

The PM runtime will be left disabled for the device if its
.suspend_late() callback fails and async suspend is not allowed
for this device. In this case device will not be added in
dpm_late_early_list and dpm_resume_early() will ignore this
device, as result PM runtime will be disabled for it forever
(side effect: after 8 subsequent failures for the same device
the PM runtime will be reenabled due to disable_depth overflow).

To fix this problem, add devices to dpm_late_early_list regardless
of whether or not device_suspend_late() returns errors for them.

That will ensure failures in there to be handled consistently for
all devices regardless of their async suspend/resume status.

Reported-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
Tested-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/base/power/main.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1262,14 +1262,15 @@ int dpm_suspend_late(pm_message_t state)
error = device_suspend_late(dev);

+ if (!list_empty(&dev->power.entry))
+ list_move(&dev->power.entry, &dpm_late_early_list);
if (error) {
pm_dev_err(dev, state, " late", error);
- if (!list_empty(&dev->power.entry))
- list_move(&dev->power.entry, &dpm_late_early_list);

if (async_error)